1. Field of the invention
The present application relates to a novel method for manufacturing a prostaglandin analogue which is used for active ingredients of pharmaceuticals.
2. Art Related
Oxidation of hydroxyl group is an important reaction step to produce a prostaglandin analogue having keto group on the 5-membered ring and/or the omega chain of its prostanoic acid skeleton.
Swern oxidation that has been conventionally used for prostaglandin syntheses requires manufacturing equipment that can operate at a very low reaction temperature (−70 to −40C.). In addition, when the prostaglandin analogue has a carboxyl group in the molecular, protection of the carboxyl group is needed before Swern oxidation.
Traditional oxidation using heavy metal reagents such as chromic acid can be used for oxidation of compounds having carboxyl group. However, most of heavy metals are toxic and occasionally not suitable as industrial production methods for pharmaceuticals.
Although Dess-Martin oxidation also can, be used to oxidize compounds having carboxyl group, the heat- and shock-sensitivity of this oxidizing reagent is published (Chem Eng. News, Jul. 16, 3, 1990, the cited reference is incorporated into the present application by reference). In addition, this oxidizing reagent is not easily available as an industrial raw material from the market.